A packet or datagram is a piece of a message transmitted over a packet-switching network. An example of a packet-switching network is the Internet where enormous quantities of data are communicated between various network points. In the Internet environment, content to be communicated between two endpoints is broken up into packets and these packets may follow different paths whilst travelling between the endpoints. It will be appreciated that the contents of packets may be benign or malicious.
An example of malicious content in a packet is data associated with viruses, computer worms, or the like and any malicious attack may thus include such malicious content.